petersen



y 15, 1952 c. c. PETERSEN 2,603,252

GUARD FOR sAws Filed June so, 1947 2Sl-IEETS-SHEET 1 Fig? INVENTOR. Christian Gfi lersez? BY wax QM fliiorzrg y 15, 1952 ,c. c. PETERSEN 2,603,252

GUARD FOR SAWS Filed June 30, 1947 2 SHEETS-SHEET 2 37 INVENTOR.

1' 36% 2 fliiorngz Patented July 15, 1952 Q GUARD FOR SAWS Christian (hPetersen, Brooklyn, N. Y.,.

- Application June so, 1947, Serial No. 758,650 12 Claims. (01. 143-159) This invention relates to saw guards and has particular relation to that type of guard wherein there is a special protection provided against the approach of the finger of the operative toward a saw blade.

In the operation of saws and particularly circular saws there isa tendency of the operative to force the piece of work under the guard with a hand to a point where the hand is liable to come into contact with the saw blade. This tendency often results in injury to the hand. The likelihood of injury is increased when the resistance to the forward movement of the work is decreased by either the saw reaching the end of the work or by the saw coming into a softer part of the board or other material being cut, near the end of the out. l

' The primary object of this invention is the provision of an improved guard for a saw.

- Another object of the invention is the provision of a saw guard wherein, on the approach to a saw blade, the finger of the operative will encounter a movable projection which with normal persons will cause-an instinctive withdrawal of the hand from the dangerous position.

A further object of the invention is the provision of a sawguard wherein, after a warning contact with a projection when a dangerous po sition of the hand is reached, a second projection will fall into the path of the hand or finger of the operative to further intercept and provide protection against the hand or finger moving into contact with the teeth of the saw.

A still further object of the invention is the provision of a saw guard pivoted within a sawcovering main guard and having a warning projection relatively farther from the saw and a second projection relatively nearer to the saw and in position to be engaged successively by the hand or finger of the saw operative.

Another and still further object of the inven tion is the provision of a saw. guard wherein there are a plurality of projections which are so placed as to come into position to be engaged successively by the hand or finger of the operative, one being above the level of the contacting position when the other is in position for contact.

Still another object of the invention is the provision of an inner guard for the usual type of saw guard which, in the normal operation of the saw, will first warn of danger and then will prevent theroperative from accidentally having his fingers come into contact with the saw teeth.

Other and further objects of the invention will. be apparent tozone skilled in the art from a reading of the complete specification.

Referring'to the drawing wherein the invention'has been illustrated,

Fig. 1 is a vertical cross sectional view i1lus- 2 trating the preferred form section taken on the line |l of Fig. 2. 1 v

Fig. 2 is a cross sectional view on'the linev 2-2 of Fig. 1..

Fig. 3 is a view similar to Fig. 1 but showlnga pieceof work, as a board, being forced under the main guard member towarda position where it will be out by the saw. Q p Fig. 4 is a view similar to Fig. with the board in position where it has just raised the inner guard to its upper position.

Fg, 5 shows the inner guard-with the board or workbeing cut by the saw. Y a

Fig. 6 shows theinner guard with the first or; warning projection dropped topermit the stop of the inner guard to be imposition ready to drop 1 to its full protective position as the end of'theboardpassesitsedge. w Fig. 7 shows the inner guard in full protective position I- v 1 I Fig. 8 illustrates the position of the inner guard when-the operatives finger inadvertently enters the space beneath the main guard, after the board or other work has reached the end of the cut by thesaw. H l

Fig.9 is a detailed elevational end view of a; modified form of the inner guard. H I a Q. Fig.-10 is a side view of Fig.- 9 illustratinghow, the hand is held from injury.-

r Fig. 11 is a modification of the invention which utilizes-straight up and down movement instead; of pivoted movement, for the inner guard.

Fig. 12 is a detailed view of the inner guard 36 with the surface of the projection 36a roughened.

"Similar reference characters refer to the same or similar parts drawing. I The illustration of the invention in the drawing and the description in .the specification refer to the construction as-applied to a circular saw but the invention may be used with any saw-for which it is adapted. V In the form of the invention illustrated in Figs. 1 to 8, 30 designates the base or standard of a circular saw and 3l the tableupon which the work rests when beingcut by the saw. Mounted in bearings just below the'table surface is a shaft- 32 which supports the saw 33. Abov the saw 33 is mounted a saw guard 34 which is of a very usual construction and movable in a substantially vertical plane.- i v .j.

This usual or outer guard 34 providesa pro-v tecting cover for the sawandis intended to prevent accidental contact of the hands and fingers of the operative with the teeth of, the saw.

The guard 34 as shown, has a top and sides but isopen at the bottom and has a periphery which, when the saw is not in use, is normally in contact with the top surface of the table 3|.

of the invention; he

throughout the specification and hands and the fingers, thus preventing their contact with the teeth of the saw.

At the end of the guard nearest .the operative,

and in the illustrated form, though not necessarily, in the sides thereof, I provide bearingsior" a pivot 35. This pivot 35 supports, at one end, the inner guard member 36. The guard member 36 is of a suitable shape which preferably will first warn the operative by the-latter com-- ing into oontact'witha-portionof its-structure and if movement by the' hand or finger -of---the operative is continued toward the saw, -a-stop portion will present itself a-nd'bar furih'er movement; thus preventingcontact-with the saw tee h;

Adjacent the pivot. the- -inner'guard '38 hasa projection or finger 38a,- which when the'saw is not in" use projects-to a position ofcon act with the table'3 I. Ate. portion of the inner-guard 38 which is more remote i'romthe p vot 35 than the projection or finger 36a, there is provi ed-a portion which I term the obstructing projection. Thissecond proiection I-have designated by the reference character 3617. Between the proieotion or finger 35aand the-obstructing pro- Jection 36b, is a spacing 350. This spacing'itc may be of a size to receive one or-morefingers of the operativewithout interference ith the vertical swinging of the inner guard 36 as willmore clearly laterappear:

ln'the normal operation- 'ofthe saw, theboard' or other-- work 31 is brought up to and 'against the inclined -portion"3 4a oftheouter'guard member 34 which raises the guard to permit the work to pass thereunder: As-the;forwardedge'or-the work 31 reachesithe projection 360:,- the inner guard *member '38 is raised until the projec ion 36a is levelwith thebottom; periphery of-theouter guard: This position of the-projection36a,-places the second-projection 36b; above the surfaceof the work;

The inner guardmember 38-remainsin; the

position until the end ofthe" work approachesthe saw teeth. As soon as the end of the workpasses the-second projectionifib pf'the-inner guard -36,

the projection will drop on the opera-tive s finger upper portion of the;guard=at oneendland to any other suitable point ;as the outer .guardLas at flb.

In order to provide suflicienticlearancebetween the sides of the guard; 3 B, ther :is: placed a;separating washer38 which prevents contact between the -guardandthe sides ofthe outer. guard'jl.

In'Fi'gss 9 -and 10 'I have illustrated. amodified form; of the invention wherein instead of'having a unitaryinner guard member-36, there are provided a plurality of sectional coacting parts placed side by side and supported byandon guard. when the end of the work I31 is about to reach the saw teeth, the edge of the work I31 will pass beyond the lower projections correspondingjtojtheprojections 36a and then beyond theflnger ends of the inner guard members I36a, I35band I330. These ends, because of the separation of the members I36a, I36!) and I36c, will fallby gravity, orsprin independently ofyeach other,- as .so.on;-asthey are;not supported by the work- Because ofzthenormal angularity of-po,

sitionxoffthe hand and fingers with relation-to the plane of the saw, some of the ends,qcorrepondingrtothe projections 360, will, fallinrst. Any such guard memberwill at once obstruct the; passage ofjjthe finger-or hand of the operative, eit her by placingitself in front of the finger or hand or-by ccntactwith the upper surface of the same.v

In the caseof both types of inner guards, 36 and I36a, I36?) and Be, if the board or work 31 is of greater thickness than the finger or hand at the point of contact with. the work, then as soon as thein-nerguard member projections 36a, I35rc, I381 or I362 are passed by thework 31, the

inner guardmember so-passed-will atoncedrop upon the finger or hand ofthe operative andgivepita. grip whichwill stopmovementtoward the saw teeth. If, on.theother.ha nd, theworkiil of lessthickness .thanthe fingeror hand of the operative, then the rflngerprv hand will he. posi tively stopped in its forwardemovement. as soon as the inner guardis reached. and before the second proiectionof theinner guard reaches the endofthe work 31.

Incase. the;finger ;or hand is about the same heightasthe end of the workjl, then the normaljtaper of the, hand orfinger will provide the innerguardwithaplace to. exert its influence on the forward movement of the hand or finger. However, the repeatedwarninggiven by thefirst and secondprojectionsoi' the inner guard are suflicient. to, preventaccidental contact of .the hand orfmgers with thesaw teeth.

It is to benoted that when-the guard sections I364, I36band I360 areusedthepassage of the fingers to a dangerous position ismade still more diflicult since withethefingers and hand at an. oblique position, as usually used, one or more of the guard sections will surely obstruct the move-- mentof the finger or hand and prevent accidental-contact with the saw.

While wilful violation of safety codes by the operatives of'machines cannot be prevented, it ,is believed that the instant invention will provide full protection to all users who do not take definite action to prevent the safety de ice from acting for their protection.

In the form illustrated in Fig. 11, the guard 23B is shown as mounted slidably in guide means 235. In this form,'the guard 236 moves up and down substantially vertically and its projections 236a and 23Gb have the same distance of travel. In this form, the projection 236a extends downwardly slightly farther than the projection 23Gb. The latter may, if desired, be provided with a roughened end as shown in Fig. 12 for the end 35. The guard membersmay be made of'metal or and support, may be made without departing from the'spirit of the invention and within its scope as claimed.

- Having described my invention, what I claim is:

l. A protective guard means for a saw come 6 guardmeans supported from the outerguard and having a plurality of successive'work engaging projections at difierent levelswith aspace between the projections of a size to receive a finger of the operative, the projections being in positionrelative to the saw to drop into the space between the operative and the saw blade, the projection nearest the saw having guiding means for guiding it in a generally vertical-movement and having a substantially vertical finger-contacting surface in front of the saw to form anabutment stop to prevent contact of the finger with the saw.

5. A 'protective guard means for a saw com-' prising an outer guard for restingon the top surface of the Work'being cut,'an integral inner prising an outer guard-in position for resting on" the-top "surface of the work being cut, the outer guard having side portions, an integral inneri guard-means within the outergu'ard and between the operator. and the place of cutting of the saw, the inner guard means comprising a projection movable to a position in front of the place of cutting of the saw and in the path of the operatives hand, and a second projection between the first projection and the saw position, the projectons being movable up and down simultaneously, the second projection having guiding means for guiding it in a generally vertical movement and having a substantially vertical fingercontacting surface .in front of the saw to form an abutment stop to prevent contact of the finger with the saw.

2. A protective guard means for a saw comprising'an outer guard for resting on the top surface of the work being cut, the outer guard guard means pivotally' supported with relation" to the outer guard and having'a plurality'of' unequally spaced projections normally tending to approach the top of the table in front of the saw cutting edge, the projection nearestthe saw having guiding means-for guiding it in a gen-g erally vertical movement and having a substan-' having side portions, an integral inner guard 7 means supported from the sides of the outer guard and movable with relation thereto, to'a place in the path of the hand of the operator; the inner guard means having two successive projections along the path of the work and movable up and down simultaneously, the projection nearest the ,saw having guiding means for guiding it in a generally vertical movement and having a substantially vertical finger-contacting surface in front of the saw to form an abutment stop toprevent contact of the finger withthe saw.

3. A guard means for a saw comprising an outer guard for resting on the top surface of the work being cut, an integral inner guard means mounted on and supported from the outer, guard and movable up and down with relation thereto, the inner guard having a plurality of projections at different levels, one of which is in front ofrthe saw in position to contact the work as it starts toward the saw and has a beveled face to raise the inner guard on contact with the Work and another projection substantially rigid with the first contacted projection in a relative position to be held out of a contacting position with the work while the first contacted pro- J'ection is in contact with the work, and between the first projection and the saw to be permitted to contact the work as the work passes out from under the first contacted projection, the projection nearest the saw having guiding means for guiding it in a generally vertical movement and having a substantially vertical finger-contacting surface in front of the saw to form an abutment stop to prevent contact of the finger with the saw.

4. A protective guard means for a saw comprising an outer guard for resting on the top surface of the work being cut, an integral inner tially vertical finger-contacting surface in front of the saw to form an abutment stop to prevent contact of the finger with the saw.

6. A protective guard means for a saw comprising an outer guard for resting on the top surface of work being cut, an integral inner guard means pivotally sup-ported with relation to the outer guard and having spaced-projec-' tions at varying distances from the saw edge, the projections normally'tending to approach the" top of the table between the operative and the saw cutting edge, the projection nearest the saw having guiding means'for guiding itin a generally vertical movement and having a substantially vertical finger-contacting surface in front of thesaw to form an abutment stop topreven t contact'of the finger with the saw. e w

'7. A protective guard means for a saw comprising an integral guard unit having a plurality of relatively rigid projections in position in front, of the saw cutting edge, and guiding means for guiding the guard projections in a, vertical plane at different levels,'and substantially in the plane of the saw and at varying distances from the cutting edge of the saw and normally tending to approach the top surface of the table in front of the saw, the "projections being placed at different levels on the guard member so that, as the work passes from under the first projection, the

other projection will'come into contact with the upper surface of the work and permit 'the firstnamed projection to come to a level lower than the upper surface of the work, the projection nearest the saw having guiding means for guiding in a generally vertical movement and having a substantially vertical finger-contacting surface in front of the saw to form an abutment stop to prevent contact of the finger with the saw.

8. A protective guard means for a saw comprising a guard member movable substantially in a vertical plane and having a rigid unit provided with a plurality of relatively rigid projections substantially in the plane of the saw and at varying distances from the cutting edge of the saw and normally tending to approach the top surface of the table in front of the saw, the projections of the guard being spaced a sufficient distance apart to permit the entry of a finger of the operator therebetween, the projection nearest the saw having guiding means for guid ing it in a generally vertical movement and hav- 7 mgaazsubstantially verticalfingerycontactingsmiacmin. gi-ront .01 s thesaw to: :torm an; abutment. stonrtorpreventcontact,ottheafingerwith.thesaw.

A jPI0te.C 1V6- guard ,meansfor a saw com,- prising, a.. pivcteds and member. movable--c sub.

stantially in -a vertical plane;and.having;its;,p ivot between: :the; position -of theI operator and 1 .the. cuttin zedgeof 15118458 and-havineaa stop proiectionwnormally, tending to approach. the-topv suriaceof the. table between.:the. cutting:.-edge of. the. saw and the. pivo anda secondcstop P113186:- tionvrigid: withthe; first projection of the guard. member spaced sufficiently from the, filritenamed proiection o brovideeatspace-mraiflnger of the perator. :thewproiection nearest-thesaw having;

second projectiononthe guard member. and-in- 0 tegralwiththe first projection spaced. sufficiently fromthe .first-named projection. to provide .a space for, a finger of the operator, this second projection being farther, from the cuttingedge of :the-zsaw than the. first-named, projection .and being, out .of the plane passing: through. thepivot andfirst .proj ection and so placed. on. the guard;

that. when the work clears the second projection-and said secondprojection moves. down-' wardly.this latter will.come to .a lower levelthan either the upper. surface. of. the work. or. thefirst named projectiomtheprojection nearest the saw having guidine. means for guiding it in. a generally vertical movementandhaving a substantially vertical finger-contacting surface infront of the saw to form an abutment. stop ,to prevent contactoi the finger with the, saw.

..11..'A.protective guard means fora saw com.- prising an outer guard for restingon the/top of. the work being cut, an integral inner guard means pivotally mounted on and supported by the. outer, guard, the inner guard having a. first projectioninthe path of. the work and a stop abutment projection normally tending to, swing.- ingly, approach. theto of. the table. in [front of.

8. the saw cutting edge, ,the, first. proiectionzbeinz in the- -path, of the. work' to. be first contacted thereby, sand mounted;on-.-the inner guardiin position to, .hold the stop abutment projection. out of the path of the work until the work .has,passed the-first: pros ectiori, the stop :abutment projection being; supported: in position, withrelation to therpivot sothatits lowerxend will travel in.

a substantially vertical movement and having .-a substantially vertical finger-:contaeting surface.

12; A. protective guard; means. fora saw comprisingaipivotza. support; for thepivot; av pivoted guarclmembenon the: pivot and-swingin mowable substantially in a vertical .planaxthe pivot;

being between-the:- position .:0f. the operator-1nd the-.tcuttng edge. ofxthezsaw; the guard, having a proiectioxr betweenzthev pivotand-the saw position, a :stop: abutment; projection. ant-the; guard betweenuthe'iirst; projection and. thesaw posietion and .normallytendingttmapproach .the table.-

surface between the pivot and. the. position. ,of thesaw "cutting edge, :the pivot w and proiections; being so placed relative; to. each gotherthanlinea passing through therespective projection ends and: the pivot will make different angles with.

relation tothe horizontal, so that when work clears. the first projection, the stop abutment projectionv will move downwardlyto a lower level than the upper surface ofthe work andpermit the stop abutment to come in contact with the work, the stop abutment projection being-supported in position with relation to the pivot. so that its lower end will travel in a substantially vertical movement, the stop abutment having a substantially vertical finger-contactingsurface.

CHRISTIAN C. PETERSEN.

ltEFERENCES CITED The following references are of record in the 

